Adam Bigenho, tech guy for the Montgomery County Board of Elections, spent part of yesterday training election judges how to match up computer plugs at polling places Monday night as they prepare for the next day's primary.

"If something is wrong Monday night, it's a problem. If something is wrong Tuesday, it's a crisis," said Bigenho, 24, one of hundreds of ground troops in a massive mobilization by local officials to ensure that all systems are good to go for Tuesday's Potomac Primary.

The big question: Will everything be working smoothly, especially the touch-screen systems that have caused problems before?

Officials were optimistic as they completed their tuneups of the touch-screen voting machines that will be in wide use across Maryland and in about half of Virginia's jurisdictions. In the District, paper ballots read by optical scanners are the system of choice, with touch-screen machines used only for disabled voters or those who don't want to use the paper and scanners, said D.C. election spokesman Bill O'Field.

But this could be the end of the road for the touch screens, which resemble automated teller machines.

Once thought to be the panacea for Florida's hanging chads after the 2000 presidential contest, they are now cited by voter security experts and advocacy groups as a symbol of voting gone awry because of stories about machines crashing and questions about their susceptibility to hackers. California ditched most of them before this week's Super Tuesday contests, and Colorado hopes to get rid of them by November.

Locally, Maryland and Virginia are likely to return to the paper and scanner system in the next few years. Advocates for a system with a paper trail say the paper and scanner systems are more secure and easier to double check than the touch-screen equipment.

In Maryland's primary two years ago, there were tales of machine meltdowns, missing computer cards and a voter check-in system that frequently crashed. The problems helped unleash a movement to get rid of the touch-screen system in Maryland.

Ross Goldstein, Maryland's deputy election chief, said those problems have been ironed out.

"Voters should know that this system has been deployed successfully since 2002 with no credible claim of tampering," Goldstein said.

In Virginia, about 40 percent of voters will be using touch screens. James Alcorn, a policy adviser at the State Board of Elections, said that because the state does not use a single system, it is difficult for the entire voting apparatus to go down at once or to be susceptible to computer hackers.